DNA can be tested by

Options

A. Iodine
B. Feulgen reaction
C. Rolish test
D. Millions reagent

Answer

**Step-by-Step Solution:**

1. **Understanding DNA Testing**: DNA, or deoxyribonucleic acid, is the genetic material found in cells. Testing DNA is crucial for various biological and medical applications, including genetic research, forensic analysis, and diagnosing genetic disorders.

2. **Staining Techniques**: One common method for testing DNA involves staining techniques. These techniques help visualize DNA under a microscope, allowing scientists to identify and analyze its structure.

3. **Acid Hydrolysis**: The first step in the staining process is acid hydrolysis. This is typically done using hydrochloric acid (HCl). Acid hydrolysis breaks down the DNA structure, making it more accessible for staining.

4. **Treatment with Schiff's Reagent**: After acid hydrolysis, the next step is to treat the sample with Schiff's reagent. This reagent reacts with the components of DNA, allowing for the visualization of the DNA strands.

5. **Addition of Bisulphite Solution**: The final step involves adding a bisulphite solution. This further enhances the staining process, ensuring that the DNA is clearly distinguishable.

6. **Resulting Colors**: After completing these steps, the DNA will appear in a reddish-purple color, while the surrounding cytoplasm will be stained green. This color differentiation helps in identifying the presence of DNA in the sample.

7. **Historical Context**: This staining technique, known as the Fulgen reaction, was developed by Robert Fulgen in 1924. It has been widely used in biological research for identifying and studying DNA.

8. **Conclusion**: Therefore, DNA can be tested using the Fulgen reaction, which involves acid hydrolysis, treatment with Schiff's reagent, and the addition of bisulphite solution.